Your LinkedIn profile photo matters. It can determine if you appear likeable, competent, and influential. Try and get an interview, new client or speaking engagement if any of those three things are missing.
A profile photo can also determine if people think you are approachable, helpful, and attractive. *Cough*Dating Sites*Cough.
We make these judgements about photos quickly. In 40 milliseconds, we’re able to draw conclusions about people based on a photo.
There is a fantastic article on all the aspects of a good profile photo, according to research and science, check it out here.